Allen Park — The Detroit Lions offense was good last season and returns the pieces to be good again this year. But for the first time in a while, the ingredients for greatness are all present.

The unit’s foundation is firm, built on the arm of quarterback Matthew Stafford. Entering his 10th season, he’s established himself as one of the game’s premier passers, completing better than 65 percent of his throws each of the past three years with nearly three times as many touchdowns as interceptions.

Beyond the box score, Stafford is tough, durable and has repeatedly proven himself as one of the league’s best in crunch time.

The Lions are also the only team to return a pair of 1,000-yard receivers in Marvin Jones and Golden Tate, a duo with yin-and-yang skill sets that perfectly complement each other. Jones, the vertical threat, helps create spacing for the highly elusive Tate running underneath routes.

Last year, the Lions averaged 25.6 points per game, good for seventh in the NFL. As noted, that’s good. And, for all intents and purposes, a repeat performance would be welcomed. Still, there were some ugly, underlying warts that anchored the Lions from reaching their true potential and needed to be addressed.

Injuries are unpredictable, but for the third straight offseason, general manager Bob Quinn bolstered the starting group, using the team’s first-round pick to take Frank Ragnow. The team also invested in experienced depth.

Those were two holes the team needed to plug this offseason, but the road from good to great hinges on the performance of a pair of youngsters, capable of pushing the offense from capable to dominant: Kenny Golladay and Kerryon Johnson.

In the passing game, Golladay, the second-year receiver, is the key to taking the next step. Earlier this offseason, he admitted he had an eye on dominating.

“The coaches have high expectations, I have high expectations and I just want to open these coach’s eyes, let them to know I’m here to work hard each and every day and can make plays for this team” he said.

Most teams pine for a vertical threat. A healthy Golladay would give the Lions two. A hamstring injury limited him to 11 games as a rookie, but had he qualified, his 17 yards per catch would have ranked fourth in the league. Jones was first, at 18 yards per reception.

Beyond his knack for the deep ball, Golladay provides Stafford with a much-needed, big-bodied threat in the red zone. The young receiver showed more adept at using his frame to his advantage in training camp this season, a skill that if it carries over could make him a top option each time the Lions near the goal line.

“He’s really long, he’s big, he’s definitely — for some of the matchups that he can get into, he creates an advantage from that standpoint,” Lions coach Matt Patricia said. “He’s a physical guy, too. He can play the big-man game at the receiving position, which is great. And, again, just from a catch-radius standpoint, it gives the quarterback a big target down in the red area, too.”

Being near the top of the league in passing is almost a given for the Lions, but the offense can only be great with a reliable ground game. Blount is a nice addition and should provide the Lions with a tone-setter both early and late in games. Ameer Abdullah and Theo Riddick, a pair of reliable pass-game options out of the backfield, also return. But it’s Johnson, a second-round pick, who could blow things wide open.

We were only afforded glimpses of Johnson through the preseason. He tantalized in his debut, the opener against Oakland, leading the team with 67 yards from scrimmage on 11 touches. He also had a dazzling 57-yard run, which put his vision, burst, balance and open-field elusiveness on display, called back by a holding penalty.

In total, he averaged 4.5 yards per carry in the preseason.

The Lions coaching staff is doing their best to temper expectations, but Johnson is picking things up quickly. He’s being asked to do far more in the passing game, both as a route runner and pass protector, than he did in college and has shown minimal struggles with those assignments.

“You see him in the games and he does a nice job out of the backfield catching the football, he’s done a nice job running the ball,” Stafford said. “He’s a smart kid, intelligent kid, he wants to learn and wants to know, so pass protection is something that he’s kind of been all in on, trying to figure that out as quickly as possible. It’s not an easy thing to figure out for a young back, lots of times, but he’s done a nice job there.”

The Lions can take it slow with Johnson, given the team’s depth at the position, but he’s talented enough to quickly force his way into a meaningful role. And, as proven by a number of players in recent years, including Kareem Hunt and Alvin Kamara last season, it’s possible for a rookie running back to have an immediate impact.

“He’ll be prepared for whatever role he gets thrust into,” Lions running backs coach David Walker said. “It’s a credit to him. He’s a smart guy, works hard, works at it. And it’s a credit to those other guys around him, who are aiding him in the process.”

With Golladay and Johnson’s potential, and an answered prayer for better durability along the offensive line, the sky is the limit.

While the defense is loaded with question marks, the biggest question for the offense should be how good can it be?